DRAFT

Step 22. RaspiAudio and Raspberry Pi

Put the RaspiAudio hat on the Raspberry Pi Zero and then hot glue the RaspiAudio in place so the speakers and microphone align with the holes in the face plate.

I am terrible at soldering. So, this was challenging for me. I learned it really hurts when I tried steadying the heating element of the soldering iron with a free finger. Neosporin helped heal the wound. Here is a great soldering guide.

The wires need to be trimmed very close, and the stripped end of the wire attaching to the Raspberry Pi needs to be really short (less than 1/8 inch). I used Blue Tack to hold the wires in place while soldering.

Solder the wires from the motion sensor, LED and push button as shown in Step 12 in Part 2

Step 24. Glue Gun Strings

I always end up with glue gun strings. Cut these off.

*** STOPPED HERE ***

Have button, camera, motion sensor, switching regulator ... what can I build

• • add detailed drawing of front plate and bottom of case

  • upgrade github with latest version of scripts

  • In script on RPi, move videos, photos and microphone recordings to sub directories

  • microphone - add to script

  • change previous in this guide to reflect just having one script instead of multiple scripts

  • add video capture with date and time stamp

  • add an option to disable alert on motion detection

  • might only want to light when motion is detected

  • might only light from 6am-12am or if motion is detected time should be configurable

  • add an option to disable alert on doorbell push

  • add alexa/echo

  • add video capture with date and time stamp

  • add inside chime

  • one-way video

  • two-way communication

  • switching regulator

  • move video or photo to external storage device

add directions for box bottom to doorbell case page - take off ring outside, measure outside holes and drill holes in box - add these instructions to the box creation

https://rayshobby.net/wordpress/24vac-to-5vdc-conversion/

https://rayshobby.net/wordpress/24vac-to-5vdc-conversion/

AC-DC buck converter

• NACRO AC-DC to DC Converter AC 16-28V DC 9V 12V 24V 36V 8-40V Step Down to 5V 3A 15W Power Supply Module

• 2Pcs AC/DC to DC Step Down Buck Converter AC 5-30V DC 5-48V 24V 36V 48V to DC 2.5-35V 12V Voltage Regulator Board 2A Adjustable Volt Power Supply Module Delinx

might need to change example above about how I chose switching voltage regulator

when I took apart ring doorbell, the lines coming in were AC and not DC

Step N. Create a Switching Voltage Regulator

The doorbell chime transformer provides 16 volts, but the Raspberry Pi should only receive 5V. So, either a step down or switching voltage regulator is required. The regulator needs to provide about 300mA.

A switching regulator dissipates less heat and uses less energy. I found the schematic below on ElectroSchematics and it meets all of my requirements.

The plan is to put the regulator in the chime. There will be some voltage drop because of the resistance in the wires from the chime to the doorbell.

Step Na. Power Supply and USB Connector

The Female Micro USB Connector I used only has 4 pins. Pins 4&5 of a standard Micro USB are hardwired together. Since I only plan to use wire and ground this does not matter.

Step XD. Mechnical Chime or should I use Wi-Fi Chime

Broan NuTone Model BK115LWH

Mechanical Chime

16v C905 transformer

https://www.broan-nutone.com/en-us/product/doorbells/bk115lwh

Transformer location is in the attic by the AC units

Which circuit breaker goes to transformer

Step XQ. Start all over [about 4 times]

My last step in creating a project like this is to take everything apart. I start by reflashing the MicroSD Card and start over. I do this to ensure I haven't accidentally skipped a step, or installed something during my prototyping that is required but not listed in the steps.

References:

• • Must have features for a Smart Doorbell

  • ifixit.com I was googling small speakers without much luck, and stumbled across this site, which shows how to replace broken parts on a Ring Doorbell. The instructions show the type of speakers and microphone used. A little more searching on Mouser and I was able to find similarly sized parts.

  • Ahmed Khattab's smart doorbell - one of the best, most full featured

  • Audio:

    • • HiFiBerry miniamp datasheet

  • Doorbell Sounds

    • • Orange Free Sounds

      • SoundBible Doorbell

      • Freesound.org Doorbells

  • Voltage Regulator:

    • • BaldEngineer Voltage Regulator Tutorial - great tutorial

      • MCP1755 Schematic - this is the one I am using

      • Instructables 5v Regulator - gave my the confidence I could do this

      • Roman Black 2 transistor regulator

      • How to step down voltage

      • Voltage divider calculator go from 16v to 5v using 10Kohm and 4.6kohm resistors

  • DIY Surface Mount Soldering

  • Camera:

    • • Camera Setup - show video or pictures on MacBook via terminal window

      • Mag Pi Camera Guide - this is outstanding!

Considered and Rejected:

Power Bank: Insert a Power Bank between the chime and the doorbell. If power goes out, then the Raspberry P's MicroSD Card won't get corrupted. Power Banks require dual ports, and must be able to charge and power the RPi at the same time. The reason to reject this idea is a Power Bank is charged from a wall outlet and neither the doorbell not the chime have a nearby outlet. Link to very small power supply.

RPi 3b+/4: I like the form factor of the new generation of doorbells. The older generation would have fit a Raspberry Pi 3/4. Dimensions: 85 x 56 x 17mm, 3.35 x 2.2in. For example, Ring Gen 2 dimensions: 4.98 x 2.4 x 1.10in. Initially, I didn't think I could find small enough parts or a case to fit everything.

I was leaning towards the hard plastic case for a RPi 3 B+/4:

Aluminum Case for Raspberry Pi - this might have issues with Wi-Fi propagation

• • • • • 97.79 x 64.01 x 34.29 m

        • ~3-7/8 x 2-1/2 x 1-3/8 in

        • Needs to be painted black

Polycarbonate for Raspberry Pi

• • • • • 114.30 x 66.80 x 52.07 mm

        • 4-1/2 x 2-5/8 x 2-1/16 in

Hard Plastic Case

• • • • • 107.95 x 66.80 x 32.26 mm

        • 4-1/4 x 2-5/8 x 1.1/4 in